Economic impact of tolvaptan treatment vs. fluid restriction based on real-world data among hospitalized patients with heart failure and hyponatremia

OBJECTIVES: To estimate the cost difference associated with tolvaptan treatment vs. fluid restriction (FR) among hospitalized patients with heart failure (HF) and hyponatremia (HN) based on a real-world registry of HN patients. METHODS: An Excel-based economic model was developed to evaluate the cost impact of tolvaptan treatment vs. FR. Model input for hospital length of stay (LOS) was based on published data from the Hyponatremia Registry (HNR). Based on HNR data, tolvaptan-treated patients had a 2-day (median) shorter LOS compared to FR. Real-world effectiveness of tolvaptan treatment from the HNR was applied to a national sample of inpatients visits from the Premier Hospital database to estimate the potential LOS-related cost difference between tolvaptan treatment and FR. A one-way sensitivity and multivariable Monte Carlo sensitivity analysis were conducted. RESULTS: Economic modeling results of the base-case analysis indicated that among hospitalized patients with HF, the hospital cost per admission, not including HN drug cost, was $3453 lower among patients treated with tolvaptan vs. FR, due to the shorter LOS associated with tolvaptan treatment. At wholesale acquisition cost of $362 per day and an average treatment duration of 3.2 days, the pharmacy cost of tolvaptan treatment per admission was estimated at $1157. Thus, after factoring the decrease in hospital medical costs and increase in pharmacy costs associated with tolvaptan treatment, results indicated a cost-offset opportunity of -$2296 per admission for patients treated with tolvaptan versus FR. Results of the sensitivity analyses were consistent with the base-case analysis. LIMITATIONS: The model derives inputs from real-world observational data. No causal relationship can be inferred from this analysis. CONCLUSIONS: Based on this economic analysis, tolvaptan treatment vs. FR among hospitalized patients with HF and HN may be associated with lower hospital-related costs, which offset the increase in pharmacy costs associated with tolvaptan treatment.